Bert Gerards
Centrum Wiskunde & Informatica
third workshop on graphs and matroids, maastricht, 29 july - 4 august 2012
I work in Combinatorial Optimization. My main research interest is Matroid Theory. With Jim Geelen and Geoff Whittle, I work on generalizing Robertson and Seymour's Graph Minor Theory to matroids representable over any fixed finite field. Our targets are the conjectures by Robertson and Seymour that such matroids are well-quasi-ordered by minors and can be tested in polynomial time for having a specific minor, and Rota's conjecture that such representability can be characterized by finitely many excluded minors. Challenge and bulk of the work is to understand the structure of minor-closed classes of the matroids over the specific field.

I am also professor in the University of Waterloo Department Combinatorics & Optimization and the Maastricht University School of Business and Economics. Recent postdocs of mine are Tony Huynh and Stefan van Zwam.


Publications (click on item for pdf)

Characterizing graphic matroids by a system of linear equations - with J. Geelen (submitted)

On inequivalent representations of matroids over non-prime fields - with J. Geelen and G. Whittle

Tangles, tree-decompositions, and grids in matroids - with J. Geelen and G. Whittle

Excluding a group-labelled graph - with J. Geelen

On the odd-minor variant of Hadwicher's conjecture - with J. Geelen, B. Reed, P. Seymour and A. Vetta

Packing odd circuits - with M. Conforti

Excluding a planar graph from GF(q)-representable matroids - with J. Geelen and G. Whittle

Mixed-integer vertex covers on bipartite graphs - with M. Conforti and G. Zambelli

Packing non-zero A-paths in group-labeled graphs - with M. Chudnovski, J. Geelen, L. Goddyn, M. Lohman and P. Seymour

Obstructions to branch-decomposition of matroids - with J. Geelen, N. Robertson and G. Whittle

Matroid T-connectivity - with J. Geelen and G. Whittle

On Rota's Conjecture and excluded minors containing large projective geometries - with J. Geelen and G. Whittle

Regular matroid decomposition via signed graphs - with J. Geelen

On the excluded minors for the matroids of branch-width k - with J. Geelen, N. Robertson and G. Whittle

Disjoint cocircuits in matroids with large rank - with J. Geelen and G. Whittle

Note on: N.E. Aguilera, M.S. Escalante, G.L. Nasini, "A Generalization of the Perfect Graph Theorem under the Disjunctive Index" - with G. Mároti and A. Schrijver

Branch width and well-quasi-ordering in matroids and graphs - with J. Geelen and G. Whittle .

The excluded minors for GF(4)-representable matroids - with J. Geelen and A. Kapoor

A theorem of Truemper - with M. Conforti and A. Kapoor

Strong orientations without even directed circuits - with F.B. Shepherd

The graphs with all subgraphs t-perfect - with F.B. Shepherd

On Tutte's characterization of graphic matroids - a graphic proof.

A characterization of box 1/d-integral binary clutters - with M. Laurent

An orientation theorem for graphs

On shortest T-joins and packing T-cuts

Compact systems for T-join and perfect matching polyhedra of graphs with bounded genus

On matrices and cutting planes

A short proof of Tutte's characterization of totally unimodular matrices

An extension of König's theorem to graphs with no odd-K4

Homomorphisms of graphs into odd circuits

Total dual integrality implies local strong unimodularity - with A. Sebö

Matrices with the Edmonds-Johnson property - with A. Schrijver

Sensitivity theorems in integer linear programming - with W. Cook, A. Schrijver and É. Tardos

Testing the odd bicycle wheel inequalities for the bipartite subgraph polytope

Spectral localization in Banach algebras - with S. Ackermans

Survey articles, monograph, etc.

Towards a matroid-minor structure theory - with J. Geelen and G. Whittle

Towards a structure theory for matrices and matroids - with J. Geelen and G. Whittle

Matching

Multicommodity flows and polyhedra

Graphs and polyhedra - Binary spaces and cutting planes

Polyhedral combinatorics in combinatorial optimization - with A. Kolen

Edited

Eighth MPS Conference on Integer Programming and Combinatorial Optimization - with K. Aardal

Unpublished

On 2-vertex connected orientations

Odd paths and circuits in planar graphs with two odd faces

Onion skins in oriented matroids - with W. Hochstättler

cwi disclaimer